I 'm still not sure why I brought this book. The title made it sound a like it was written by a get rich quick seminar promoter. What I found was a coherent story of a successful investor who adopted an investment startegy that, while highly aggressive (by my standards at least), sounded similar to the way some hedge funds invest. The other interesting feature was how James DePorre had to turn his life around after becoming deaf as an adult and losing his career as a lawyer as he struggled to adapt.
The good features of Invest Like A Shark incuded:
1. a chapter on why a lot of conventional advice will deliver mediocre results. Some of these were (for me) new ways of looking at old issues;
2. a chapter on some of the myths of Wall Street. Some of these I agreed with. Some I was not convinced by. There was nothing in this section I found new (and I did wonder why the author felt that some of these were considered myths);
3. an emphasis on market psychology. There are studies which suggest that psychology plays a big part in determining successor failure as an investor and DePorre's comments on this area were interesting;
4. a clearly defined set of principles to be a "shark" investor. These were interesting. The way in which DePorre addressed risk management through diversification and cutting losses sounded a lot like some of the hedge fund managers interviewed in Hedge Hunters .
Things I didn't like:
5. too much emphasis on being a "shark". He really did sound like a shady seminar shyster at times. Even for a short book (195 pages) there seemed to be a bit too much repetition. This was a shame as the underlying message was actually quite good (regardless of whether you want to be an aggressive trader or not);
6. not enough data to support his views. DePorre argues from principles and sometimes produces examples to support his views, but no real evidential support is given. This is the major failing of the book.
In conclusion, the book is a reasonably interesting read and combines some useful ideas and interesting observations with a coherent but aggressive investment strategy. Unfortunately, the absence of supporting research data and a slightly cheesy writing style make the book less than compelling reading. If you want to read about how to trade aggressively, books about hedge fund managers and some other books on trading make better and more interesting reading.